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J M Montalvo

Publications and source records attributed to J M Montalvo.

12 recordsLinked to original sources
PubMed1985

Pituitary gonadotropin-independent male-limited autosomal dominant sexual precocity in nine generations: familial testotoxicosis.

A recently described, distinct form of male sexual precocity is characterized by premature Leydig and germinal cell maturation in the absence of pituitary gonadotropin stimulation. Analysis of a nine-generation kindred with at least 28 affected males supports sex-limited autosomal dominant transmission. Three boys, with precocious sexual development at 1 to 4 years of age, had low basal plasma gonadotropin values without pubertal-type pulsatility and a minimal rise in luteinizing hormone after acute stimulation with luteinizing hormone releasing factor or its potent analog D-Trp6-Pro9-NEt-LRF, distinguishing them from boys with true precocious puberty. Two affected adults had a mature luteinizing hormone response to LRF. Testicular biopsies showed a progression of abnormalities in the seminiferous tubules from childhood to maturity; in one adult this disorder was associated with marked oligospermia and selective elevation of plasma follicle-stimulating hormone. The findings are consistent with an inherited intratesticular defect. Furthermore, the majority of cases of familial male sexual precocity seem to be examples of this disorder rather than central or true precocious puberty.

Child↗
PubMedDate not supplied

Regulation of aldosterone biosynthesis during sodium deficiency. Evidence for an essential role of the pituitary gland.

The aldosterone response to adrenocorticotropic hormone (ACTH) and angiotensin II (AII) was evaluated in patients with pituitary insufficiency before and after dietary sodium restriction (10 mEq Na+/day for 12 days). On normal sodium intake, plasma aldosterone concentration and plasma cortisol concentration failed to change from control levels in response to a single injection of ACTH or to a continuous 1-hour infusion of AII in patients with pituitary insufficiency. In response to dietary sodium restriction for 12 days, plasma renin activity (PRA) increased fivefold in patients with pituitary insufficiency, while plasma aldosterone concentration failed to increase significantly, averaging 11.0 +/- 3.1 before and 12.3 +/- 3.7 ng/dl (ns, p greater than 0.05) after sodium deficiency. Although aldosterone secretion failed to increase during sodium deficiency, the patients came into balance at 10 mEq without a significant change in arterial blood pressure (BP). In sharp contrast to the lack of aldosterone response to ACTH before sodium deficiency, plasma aldosterone concentration increased markedly from 12.9 +/- 3.3 to 156 +/- 17.3 ng/dl (p less than 0.001) in response to ACTH after sodium deficiency. Although the adrenal glomerulosa cells were markedly sensitive to ACTH during sodium deficiency, they remained almost totally refractory to AII since aldosterone secretion failed to increase significantly in response to continuous infusion of a pressor dose of AII for 1 hour. Replacement therapy with ACTH gel for 3 months in patients with pituitary insufficiency failed to restore a normal aldosterone response to either ACTH or AII. These data demonstrate that some non-ACTH pituitary factor(s) is essential for a normal aldosterone response to ACTH, AII, and sodium deficiency.

Adrenocorticotropic Hormone↗